¥1,400,000 (Direct Cost : ¥1,400,000)

In this study, we have examined the effect of surgical stress on cancer progression of peritoneal dissemination and angiogenesis of cancer nodules in the peritoneal cavity.(1) Establishment of animal model of peritoneal dissemination, using nude mouse(2) Development of convenient CO2 pneumoperitoneum model using mouse(Surg Endosc Laparosc, 1999)(3) The effect of surgical stress on growth of peritoneal depositsForty mice were divided randomly into two groups such as pneumoperitoneum (5mm Hg, 30min) and laparotomy (3cm, 30min) group. After injection of gastric cancer cells (105 cells) of MNK45 into the peritoneal cavity, each operative procedure was performed. The mice were killed 3 weeks after the operative procedure and the number and size of peritoneal deposits were measured. We found that there was no significantly difference in the number, but the size in laparotomy group was larger than in pneumoperitoneal group.(4) The induction of angiogenesis factors in peritoneal cancer depositsTo clarify the mechanism of it, we examined the induction of angiogenesis factors including VEGF and bFGF by RT-PCR method. The peak level of the induction of VEGF in laparotomy group was significantly higher than in pneumoperitoneum group (preparing manuscript).These data suggest that surgical stress may sitimulate the growth of peritoneal deposits by induction of an angiogenesis factor, VEGF.